KR101491442B1 - Dry absorbent or inorganic carbonate conversion agent for carbon dioxide capture and storage using fly ash, and method for manufacturing thereof - Google Patents

Abstract

The present invention relates to an active ingredient capable of selectively recovering carbon dioxide from a gas stream by selectively reacting with carbon dioxide, and a carbon dioxide dry sorbent or carbon dioxide inorganic carbonate conversion agent containing a fly as a support. The carbon dioxide dry sorbent or carbon dioxide inorganic carbonate conversion agent according to the present invention can efficiently treat coal fly ash that is classified as waste by containing coal fly ash as a support, and is easy to manufacture and does not use harmful organic substances Not only is it environmentally friendly, it can also increase the carbon dioxide uptake by about 24% and reduce the desorption temperature by more than 100 ° C, which is about 22% less than the carbon dioxide dry sorbent or carbon dioxide inorganic carbonate conversion agent that does not contain fly ash It is possible to store carbon dioxide by converting carbon dioxide into carbonates when it is difficult to regenerate the carbon dioxide, which is advantageous in process design flexibility and can be used as an additive for building materials. Therefore, Suction The carbon dioxide or an inorganic carbonate conversion can be effectively used to replace the first.

Description

Technical Field The present invention relates to a dry absorbent or inorganic carbonate conversion agent for capturing and storing carbon dioxide using fly ash,

The present invention relates to a method for recovering carbon dioxide, which is generated by the use of fossil fuels in industrial plants such as thermal power plants and discharged to the atmosphere, by dry absorption technology or inorganic carbonate conversion technology before being discharged to the atmosphere, .

Carbon dioxide is one of the greenhouse gases known to have the greatest impact on global warming due to increased emissions of fossil fuels. In particular, since large amounts of carbon dioxide are generated in large-scale combustion facilities such as thermal power plants, steel mills, petrochemicals, and cement industries, if they do not control their CO 2 emissions, global warming may cause global warming. Accordingly, researches on carbon dioxide capture and storage technologies are being conducted to minimize the emission of carbon dioxide to the atmosphere.

The basic concept of carbon dioxide capture and storage technology is collectively referred to as sequestration or storage, which is a method of capturing generated carbon dioxide and treating it without releasing it to the atmosphere. Generally, carbon capture and storage (CCS) Storage). CCS will be one of a series of ways to stabilize greenhouse gas concentrations while continuing to use fossil fuels. Carbon dioxide capture and storage technologies have the potential to reduce total cost of ownership and increase diversity in achieving greenhouse gas emission reductions.

Carbon dioxide capture techniques can be classified into three types: post-combustion, precombustion, and oxyfuel combustion. Methods for recovering carbon dioxide after combustion include absorption methods such as wet scrubbing and dry scrubbing, adsorption, membrane separation, and deep-sea cooling. To date, commercialization technology is still costly and energy-consuming to recover or separate CO ₂ from large-scale flue-gases, which requires technological innovation.

On the other hand, the technology of using dry absorbent has the principle that solid particles are used instead of the conventional wet solution to react with CO ₂ to become a stable compound, and CO ₂ is discharged under other conditions and regenerated as an original compound. Various dry sorbents such as alkali metals, alkaline earth metals, and dry amines have been developed as materials. It is expected that the use of the dry absorbent will overcome the problem of high energy consumption in the regeneration process because the waste water is not generated and the corrosion problem is small.

Conventionally developed dry absorbent related technologies are as follows.

As an example of a description of a dry playback absorbents, U.S. Patent No. 4,810,266, the dry playback absorbent capable of maintaining the initial carbon dioxide (CO ₂₎ absorption capacity by carrying the amine on tansobun itself as a support subjected to continuous absorption / regeneration tests for 300 hours .

A similar concept of regenerating solid amine-absorbing agent is disclosed in U.S. Patent No. 5,876,488, which discloses a method of improving the absorption rate and regeneration rate of carbon dioxide at a room temperature by impregnating a high concentration amine with a solid polymer scaffold, And it has been confirmed that it can be used in a fixed layer. In addition, U.S. Patent No. 5,091,358 discloses an absorbent comprising carbon dioxide (Ag ₂ CO ₃ ) and carbon dioxide (CO ₂ ) absorption promoting agent Cs ₂ CO ₃ as an active ingredient in a porous diatomaceous earth support, It is possible to absorb / regenerate carbon dioxide (CO ₂ ).

Since then, researchers have also used narcotic alkaline salts (eg, CsF) as a way to increase the absorption rate of carbon dioxide (CO ₂ ) in confined spaces with low relative humidity.

Korean Patent Laid-Open Publication No. 10-2011-0006073 discloses a method for producing a silica monolith having an amine-supported layer pore structure and a carbon dioxide dry absorbing agent using the same. In Korean Patent Registration No. 10-0803325, Carbon dioxide solid absorbent containing carbon dioxide.

However, conventionally developed carbon dioxide absorbent for dry regeneration generally uses activated carbon, zeolite, bentonite or the like as a support material. Since these materials are expensive materials, most of them are difficult to commercialize in economical terms. There is a problem of energy consumption because it is necessary to use a high temperature.

Accordingly, an object of the present invention is to economically separate and recover carbon dioxide generated in a large-scale combustion facility such as a thermal power plant, a steel mill, a petrochemical industry, and a cement industry, thereby restricting CO _{2 from} being discharged into the atmosphere and ultimately solving environmental problems such as global warming suitable for bulk CO ₂ recovery techniques for, and also to economical and provide a carbon dioxide or carbon dioxide, inorganic carbonates dry absorbent converting agent and a method of manufacturing the same which meet the carbon dioxide once the low-energy consumption receiving process.

In order to achieve the above object, the present invention provides a carbon dioxide dry absorbent or a carbon dioxide inorganic carbonate conversion agent containing a fly as a support.

The present invention also provides a process for preparing the carbon dioxide dry sorbent or the carbon dioxide inorganic carbonate conversion agent.

The carbon dioxide dry sorbent or carbon dioxide inorganic carbonate conversion agent according to the present invention can efficiently treat coal fly ash that is classified as waste by containing coal fly ash as a support, and is easy to manufacture and does not use harmful organic substances In addition to being environmentally friendly, the produced carbon dioxide dry sorbent or carbon dioxide inorganic carbonate conversion agent can increase the carbon dioxide absorption rate or conversion rate by about 24% compared with a carbon dioxide dry sorbent or carbon dioxide inorganic carbonate conversion agent without added fly ash, It is possible to reduce the amount of energy required for regeneration by about 22%, and when it is difficult to regenerate, carbon dioxide can be stored by converting it into inorganic carbonate, thereby enabling the storage of carbon dioxide. Can be used, it is easy to handle for the waste. Therefore, the carbon dioxide absorbent for dry regeneration according to the present invention has many advantages such as the conventional carbon dioxide dry absorbent or the carbon dioxide inorganic carbonate conversion agent.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart illustrating a method for preparing a carbon dioxide dry sorbent or carbon dioxide inorganic carbonate conversion agent according to one embodiment of the present invention.
FIG. 2 is a thermogravimetric analysis graph showing absorption / desorption performance of a carbon dioxide dry absorbent or a carbon dioxide inorganic carbonate conversion agent containing fly ash according to an embodiment of the present invention. FIG.

Hereinafter, the present invention will be described in detail.

The present invention provides a carbon dioxide dry sorbent or a carbon dioxide inorganic carbonate conversion agent comprising fly as a support.

The carbon dioxide dry absorbent or carbon dioxide inorganic carbonate conversion agent according to the present invention comprises an active ingredient and a fly as a support.

In the carbon dioxide dry absorbent or the carbon dioxide inorganic carbonate conversion agent according to the present invention, the active ingredient is a substance capable of selectively recovering and separating carbon dioxide from a gas stream by selectively reacting with carbon dioxide, wherein the alkali metal belonging to group 1 and 2 of the periodic table Or an active ingredient which can be absorbed and converted into an alkaline earth metal carbonate or a bicarbonate carbonate

The active ingredient may preferably be present in the total solid feedstock in a proportion of 50-70% by weight (weight percent by weight). As described above, the active ingredient is a substance capable of selectively recovering and separating carbon dioxide from a gas stream by selectively reacting with carbon dioxide. The active ingredient is absorbed or absorbed by an alkali metal or an alkaline earth metal carbonate or a bicarbonate carbonate belonging to Group 1 and Group 2 of the periodic table, And a combination of sodium hydroxide, which is a metal hydroxide, and calcium oxide, which is a metal oxide, may be used. When a combination of sodium hydroxide and calcium oxide is used as the active ingredient, sodium hydroxide and calcium oxide are preferably mixed in a ratio of 1: 1.

The active ingredient is not limited to a starting material for synthesis or a natural raw material, but preferably has a purity of 98% or more.

In the carbon dioxide dry absorbent or the carbon dioxide inorganic carbonate conversion agent according to the present invention, the support has properties such that the active ingredient is distributed well in the absorbent particle to increase the reactivity and adsorb or absorb the moisture required for the reaction.

Zeolite, bentonite, and the like which have hydrophilicity on their own, or can impart hydrophilicity to the absorbent, are conventionally used as supports, but they are expensive materials, and therefore they are difficult to be commercialized in terms of economy.

The present invention is characterized by using fly ash as the support.

The fly ash is a material of a porous spherical material having a specific surface area of about 2,000 to 4,000 cm 3 / g, which is discharged from various waste incineration and thermal power plants. In general, the fly ash is used as a raw material for landfill or building materials, but no case has been reported in which the fly ash is used as a support for a carbon dioxide absorbent.

The present applicant has found that when the fly ash is used as a support for a carbon dioxide absorbent, the amount of carbon dioxide absorbed increases as compared with a carbon dioxide dry absorbent or a carbon dioxide inorganic carbonate conversion agent which does not contain fly ash and the desorption temperature for recovering carbon dioxide It was confirmed that it was reduced by 100 ° C or more as compared with the carbon dioxide dry absorbent or the carbon dioxide inorganic carbonate conversion agent.

Therefore, the fly ash can be usefully used as a support for a carbon dioxide dry absorbent or a carbon dioxide inorganic carbonate conversion agent.

In the carbon dioxide absorbent according to the present invention, the fly ash is preferably a coal fly ash discharged from the coal-fired power plant in the form of waste after power generation, and preferably contains 30 to 50 wt% of the total solid feedstock. If the active ingredient is a combination of sodium hydroxide and calcium oxide, the carbon dioxide dry absorbent or the carbon dioxide inorganic carbonate conversion agent according to the present invention may contain sodium hydroxide, calcium oxide and fly ash in a weight ratio of 1: 1: 1 .

The present invention also provides a process for preparing the carbon dioxide dry sorbent or the carbon dioxide inorganic carbonate conversion agent.

The manufacturing method according to the present invention, as shown in Fig . 1 ,

A step of crushing and stirring the fly asan as an active ingredient and a support to prepare a mixture (step 1);

Adding water to the mixture for binding of the mixture prepared in step 1 (step 2);

Drying the mixture prepared in step 2 (step 3); And

(Step 4) of preparing a carbon dioxide dry absorbent or a carbon dioxide inorganic carbonate conversion agent by further pulverizing and stirring the mixture dried in step 3 above.

Hereinafter, the production method of the present invention will be described step by step.

First, Step 1 is a step of preparing a mixture by pulverizing and stirring a solid raw material containing an active ingredient and a fly as a support.

The above step is a step of preparing a mixture of an active ingredient and a support by pulverizing and stirring the above-described fly asan as the active ingredient and the support.

In the above step, milling and stirring may be performed by a method commonly used in the art. For example, a ball mill or the like may be used.

In this case, the active ingredient may be preferably 50-70 wt% (weight percentage by weight) of the total solid raw materials, and the fly ash may include 30-50 wt% of the total solid raw materials. If a combination of sodium hydroxide and calcium oxide is used as the active ingredient, sodium hydroxide, calcium oxide and fly ash can be mixed at a weight ratio of 1: 1: 1.

Next, Step 2 is a step of binding the mixture.

This step is to add water to the mixture for binding of the mixture prepared in step 1 above.

Conventionally, in the production of the carbon dioxide absorbent, a binder of an organic material is used for bonding the mixture. However, since only a small amount of water is used in the bonding, the present invention is environmentally friendly and easy to manufacture.

The amount of water to be added is not particularly limited as long as the amount of water to be added is such that the mixture can be dissolved or mixed to be uniformly bound to water, but it is preferably 1.5-3 times the molar fraction according to the theoretical stoichiometric reaction of calcium oxide and water (CaO + H ₂ O -> Ca (OH) ₂ ), where the amount of water required as a stoichiometry is 1: 1 in terms of molar ratio with respect to calcium oxide, This is because a larger amount of water must be added for uniform mixing with other ingredients. Specifically, the water is preferably added in an amount of 0.5 to 1.0 ml H ₂ O / g CaO based on the weight of the calcium oxide.

Next, Step 3 is a step of drying the mixture.

In the above step, the drying method may be a method commonly used in the art. For example, a vacuum pump or the like may be used for drying in a vacuum state.

Next, Step 4 is a step of again grinding and stirring the dried mixture in Step 3 to prepare a carbon dioxide dry absorbent or a carbon dioxide inorganic carbonate conversion agent.

In the above step, milling and stirring may be performed by a method commonly used in the art. For example, a ball mill or the like may be used.

The carbon dioxide dry sorbent or carbon dioxide inorganic carbonate conversion agent according to the present invention can efficiently treat coal fly ash that is classified as waste by containing coal fly ash as a support, and is easy to manufacture and does not use harmful organic substances In addition to being environmentally friendly, the produced carbon dioxide dry sorbent or carbon dioxide inorganic carbonate conversion agent can increase the carbon dioxide absorption rate by about 24% as compared with carbon dioxide dry sorbent without fly ash and lower the desorption temperature by more than 100 ° C, It can be reduced by about 22%. When it is difficult to regenerate, it can be treated as an inorganic carbonate conversion agent and can be used as an additive for building materials, so that it is easy to treat waste. Therefore, the carbon dioxide dry absorbent or the carbon dioxide inorganic carbonate conversion agent according to the present invention has many advantages such as the conventional carbon dioxide dry absorbent or the carbon dioxide inorganic carbonate conversion agent.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples are only the preferred embodiments of the present invention, and the present invention is not limited by the following Examples.

< Example  1>

As a support Fly ash  Used carbon dioxide dry absorbent or carbon dioxide Inorganic carbonate  Conversion agent ( WNCF )

Sodium hydroxide, calcium oxide, and coal fly ash were weighed to a weight ratio of 1: 1: 1, placed in a jar, and milled while thoroughly stirring for 24 hours using a ball mill. Thereafter, distilled water was added to 0.65 ml H ₂ O / g CaO based on the weight of calcium oxide. After adding distilled water, it was dried in a vacuum state at 50 ° C for 2 hours or more using a vacuum pump (Lab House, HS-VO27). Thereafter, the sufficiently dried sample was pulverized and stirred again to finally produce a carbon dioxide dry absorbent or a carbon dioxide inorganic carbonate conversion agent.

< Comparative Example >

Fly ash  Carbon dioxide dry absorbent or carbon dioxide Inorganic carbonate  Conversion agent ( WNC )

Carbon dioxide dry absorbent or carbon dioxide inorganic carbonate conversion agent was prepared in the same manner as in the above example, except that the coal fly ash was not contained in the mixture.

< Experimental Example >

Carbon dioxide absorption / desorption performance measurement of carbon dioxide absorbent for dry regeneration

In order to investigate the carbon dioxide absorption / desorption or conversion performance of the carbon dioxide dry absorbent or the carbon dioxide inorganic carbonate conversion agent containing the fly ash according to the present invention, the following thermogravimetric analysis was performed.

(1) Carbon dioxide absorption process

10 mg of the carbon dioxide absorbent for dry regeneration prepared in Examples and Comparative Examples were placed in a thermogravimetric analysis (TGA), and the carbon dioxide was absorbed at a rate of temperature rise of 5 ° C. per minute so that the optimum absorption temperature could be obtained from the room temperature. Respectively. As a result of the experiment, after 550 ℃, weight gain was stopped and weight loss due to degassing was observed, and the optimum absorption temperature was set at 550 ℃. The absorption period was again divided into two sections. Specifically, in the first absorption period, the sodium hydroxide in the carbon dioxide dry absorbent or the carbon dioxide inorganic carbonate conversion agent starts to absorb water from the room temperature at a temperature ranging from room temperature to the boiling point, and some of the moisture is removed or evaporated due to the absorption reaction The expected temperature is 150 ° C, and 150 ~ 550 ° C is set as the secondary section. And then cooled to room temperature (30 ° C) at 10 ° C per minute.

The weight increment in each section is shown in Tables 1 and 2 in terms of the amount of absorption based on the composition of sodium hydroxide and calcium oxide, which are active ingredients of carbon dioxide dry absorbent or carbon dioxide inorganic carbonate conversion agent.

Carbon dioxide absorption (%) Carbon dioxide dry absorbent or carbon dioxide
Inorganic carbonate conversion agent Example (WNCF) Comparative Example (WNC) The final (30-550 ° C) 75.62 51.49 Primary section (30-150 ° C) 80.90 51.68 Secondary section (150-550 ° C) 71.88 51.35

As shown in Table 1 and Fig. 2, the carbon dioxide dry absorbent or the carbon dioxide inorganic carbonate conversion agent according to the present invention showed absorption or conversion of carbon dioxide by 70% or more by containing fly as a support, It has been shown that the amount of carbon dioxide absorbed or converted is 20% higher than that of carbon dioxide absorbent for dry regeneration (about 50%).

Accordingly, it can be seen that the carbon dioxide dry absorbent or the carbon dioxide inorganic carbonate conversion agent according to the present invention effectively absorbs or converts carbon dioxide to a high absorption amount by containing fly as a support.

(2) Carbon dioxide desorption process

In the same manner as in the above (1), the thermogravimetric analysis was carried out at a heating rate of 5 ° C per minute from room temperature to 800 ° C, and the temperature at which the desorption of carbon dioxide was started was measured and shown in Table 2 and FIG.

Example (WNCF) Comparative Example (WNC) Desorption temperature (캜) 438 555

As shown in Table 2 and FIG. 2, the carbon dioxide dry sorbent or carbon dioxide inorganic carbonate conversion agent containing the fly ash according to the present invention had a desorption start temperature of 438 占 폚, which was higher than the desorption temperature Is lower than 100 캜.

Therefore, the carbon dioxide dry absorbent or the carbon dioxide inorganic carbonate conversion agent according to the present invention can efficiently treat fly ash classified as waste by containing fly as a support, and the produced carbon dioxide dry absorbent or carbon dioxide inorganic carbonate conversion agent can be added to fly ash The carbon dioxide absorption rate can be increased by about 24% and the desorption temperature can be lowered by 100 ° C or more, thereby reducing the energy required for regeneration by about 22%. Therefore, the carbon dioxide dry absorbent or the carbon dioxide- Carbon dioxide inorganic carbonate conversion agent.

The present invention has been described with reference to the preferred embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

Claims (10)

And a fly as a support capable of selectively recovering carbon dioxide from the gas stream by selectively reacting with carbon dioxide, wherein the active component is converted to an alkali metal or alkaline earth metal carbonate or a bionic carbonate belonging to Groups 1 and 2 of the Periodic Table A carbon dioxide dry absorbent or a carbon dioxide inorganic carbonate conversion agent, characterized in that it is sodium hydroxide which is a metal hydroxide and calcium oxide which is a metal oxide;
The fly ash is a coal fly ash discharged from a coal-fired power plant in the form of waste after power generation.
Wherein the content of the active ingredient is 50-70 wt% and the content of the fly ash is 30-50 wt%
A carbon dioxide dry sorbent or carbon dioxide inorganic carbonate conversion agent characterized in that sodium hydroxide and calcium oxide as active components and coal fly as a support are contained in a weight ratio of 1: 1: 1 as sodium hydroxide, calcium oxide and coal fly ash. delete delete delete delete delete delete delete (Step 1) of preparing a mixture by mixing sodium hydroxide and calcium oxide as active ingredients and coal fly as a support in a weight ratio of 1: 1: 1, pulverizing and stirring the mixture;
Adding water of 0.5-1.0 ml_H ₂ O / g CaO based on the weight of calcium oxide (step 2) to the mixture for binding of the mixture prepared in the step 1;
Drying the mixture prepared in step 2 (step 3); And
(Step 4) of producing a carbon dioxide dry absorbent or a carbon dioxide inorganic carbonate conversion agent by re-pulverizing and stirring the mixture dried in step 3 above (step 4). delete

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